Communication

Question 1

Multicellular

Answer 1

Made up of many cells.

Question 2

Hormone

Answer 2

A chemical secreted by an endocrine gland, which brings about a response in an organ elsewhere in the body.

Question 3

Nerve

Answer 3

A group of axons and dendrons, surrounded by a protective covering.

Question 4

Cell Signalling

Answer 4

Communication between one cell and another

Question 5

Homeostasis

Answer 5

The maintenance of a stable internal environment.

Question 6

Negative Feedback

Answer 6

A mechanism by which a change in a parameter is detected and which brings about a response that moves the parameter back towards the norm.

Question 7

Receptor

Answer 7

A cell that detects a stimulus

Question 8

Effector

Answer 8

An organ that carries out an action in response to a stimulus, such as a muscle that contracts or a gland that secretes a substance

Question 9

Positive Feedback

Answer 9

A mechanism by which a change in a parameter is detected and which brings about an action that takes the parameter even further away from the norm.

Question 10

Endotherm

Answer 10

An organism that generates heat inside the body to maintain a constant body temperature no matter what the temperature of the environment

Question 11

Hypothalamus

Answer 11

A small part of the brain in the very centre of the head, which contains receptors involved in temperature regulation and osmoregulation; it is closely associated with the pituitary gland and controls the secretion of hormones from that gland.

Question 12

Core Temperature

Answer 12

The temperature deep inside the body. Approx. 37˚c in humans.

Question 13

Peripheral Receptors

Answer 13

Cells in the skin that detect a stimulus.

Question 14

Shivering

Answer 14

The rapid contraction and relaxation of muscles, generating heat

Question 15

Arteriole

Answer 15

A small artery

Question 16

Vasoconstriction

Answer 16

The contraction of the smooth musicle in the walls of arterioles supplying blood to the surface of the skin, narrowing the lumen and reducing blood flow

Question 17

Sweat Glands

Answer 17

A gland in the dermis of the skin that extracts fluid from blood plasma and secretes this into a duct that carries the fluid onto the surface of the skin

Question 18

Erector Muscle

Answer 18

A muscle that raises a hair when it contracts

Question 19

Vasodilation

Answer 19

The relaxation of the smooth muscle in the walls of arterioles supplying blood to capillaries near the surface of the skin, widening the lumen and increasing blood flow

Question 20

Ectotherm

Answer 20

An organism that does not fully control body temperature by physiological means; its body temperature changes with the environmental temperature